1. Field of the Invention
This invention relates to infrastructure. Specifically, the present invention relates to communication infrastructure.
2. Description of the Related Art
Modern voice-based communication systems include circuit-switched systems and packet-switched systems. In circuit-switched systems, a circuit (e.g., one path) is established between end-users. The end-users have exclusive use of the circuit until the connection is released. In a packet-switched system, communication is also established between end-users. Messages transmitted between the end-users are segmented into packets. The packets may take different paths across the network.
In a conventional telephony system, communication is established between an end-user and switching hardware. The switching hardware may be a private branch exchange or it may be a switch located in a central office. The central office may be able to switch a call directly to a second end-user if the second end-user is connected to the central office. In the alternative, the call may be switched through an edge switch to a Public Switched Telephone Network (PSTN). Ultimately, the call reaches the second end-user.
Calls are switched based on the incoming call number, the outgoing call number, and several other parameters. Different communication links or trunks are associated with specific call numbers. A call is switched from one trunk to a different trunk to complete the call or to establish a connection. The trunks are typically linked together in a group known as a trunk group, where a trunk group is a group of trunks that can receive calls directed to a common set of phone numbers. When a call arrives at the trunk group, the switch searches (e.g., hunts) for an available trunk in the group and connects the call to that available outgoing trunk.
In order to accurately locate and switch calls in the PSTN, a numbering plan known as the North American Numbering Plan (NANP) (e.g., NPA-XXXX) is implemented in North America. However, as the name implies, there are other numbering plans in other areas of the world. In the NANP, end-users are given a specific number and the number is used to locate end-users and route calls in the network.
Routes used to access end-users may be dynamic. For example, network reconfigurations may change the route to an end-user or one path may be congested and there is a better alternative route. Therefore, routes are continually changing and updated in the network.
Switches that operate within the PSTN are often implemented as large mainframe computers or distributed workstations. Both implementations frequently use Operations Systems (OS) to function. One such OS is the routing OS, which instructs the switch on how to make a call. For example, a switch's routing translation (e.g., routing data that is stored in the switch), which contains the latest routing data, is typically loaded and updated by a routing OS.
Routing OS systems are very complex. They operate by deriving routing data, provisioning that routing data into switches in the network and coordinating the provisioning across switches such that the provisioning occurs in the correct sequence. The routing OS accepts feeds from industry databases (e.g., Local Exchange Routing Guide), as well as from other internal OS's (e.g., trunk planning, number assignment, etc.). There is a tremendous amount of logic associated with a routing OS. The routing OS is used to derive the appropriate routes across the network and then the routing OS loads the routing data into the switches. Today's switches are dependent on these complex routing OS as are the deployment of new services that depend on the routing OS.
Updating routing information using the routing OS introduces tremendous overhead and inefficiencies. For example, the translations in each switch must remain current; therefore, there is significant traffic associated with continually downloading and updating switches. In addition, since the network is constantly changing, keeping the routing OS current and updating the translations in each switch, in a timely manner, becomes a burdensome task. Should the switch translations fail to stay current, calls go uncompleted, which ultimately results in dissatisfied end-users and loss of revenue for the operating company.
Implementing network technologies, which depend on the routing OS, is an arduous task. The routing OS and the translations are often the most time-consuming aspects of implementing a network. New technologies are being developed that reduce the time to market for technology designers. However, even with the new technologies, one of the most time-consuming aspects of deploying a network is implementing the routing OS and the translations. Therefore, implementing the routing OS and translations in a network is an impediment to the quick and efficient deployment of advancing technologies.
Conventional voice communications are continually advancing. For example, packet-switched communications of voice calls have developed. Two approaches worthy of note include datagram communications and virtual circuit communications. In both forms of packet switching, voice signals are first digitized and segmented into packets. In virtual circuit communications, the packets follow a path that is established between two end-users. This may be considered a circuit-switched call that uses packets. In datagram technology, each packet is an individual unit and may follow its own path across the network from a sending end-user to a receiving end-user.
With the explosion of the Internet, voice-based communications are no longer just going over traditional voice communications networks, but are now going over the Internet. In the past, Internet networks were synonymous with data networks and the PSTN was considered a voice network. The lines between the Internet and traditional voice networks (e.g., PSTN) have blurred.
Conventional Internet protocols, such as the Transmission Control Protocol (TCP)/ Internet protocol (IP), have been adjusted to accommodate voice. As a result, technologies such as Voice-over-IP have emerged. One of the objectives of Voice-over-IP technology is to provide end-users with the ability to make telephone calls (e.g., as in the PSTN) over IP-based data networks, with a reasonable quality of service. However, the problems associated with maintaining and distributing routing information are also present. Therefore, some of the potential of Voice-over-IP is diminished since the problems associated with the routing OS are still present.
In addition to changes in the method of making voice-based calls (e.g., Voice-over-IP), the hardware used to make voice-based calls has changed. The hardware that was once used to make voice-based calls may now be implemented in software. For example, a voice-switching platform known as a softswitch is available.
A softswitch, as defined by the International Softswitch Consortium, is a software-based entity that provides call control functionality. A softswitch typically includes a Call agent (e.g., media gateway controller, softswitch), Media gateway, Signaling gateway, Feature server, Application server, Media server, and Management, provisioning and billing interfaces. A call agent provides the call logic or call control signaling for one or more media gateways. The media gateway transforms media from one transmission format to another. The signaling gateway encapsulates and transports PSTN signaling protocols over IP. The feature server provides enhanced call control services, such as network announcements, 3-way calling, call waiting, etc. The application server provides the service logic and execution for one or more applications. The media server performs media processing on packet media streams. The management, provisioning and billing interfaces provide management provisioning and billing functionality.
The components of a softswitch may be located in a single unit or may be distributed. While softswitch technology provides for more flexibility and speed in implementing communication networks, there is processing overhead required in updating the different components of a softswitch. For example, the conventional methods of updating the routing OS are once again, a time-consuming and arduous task when implementing a softswitch.
Maintaining the routing OS and translations become challenging when routing is dynamic. In a number of technologies, the call routing path changes based on the technology. Therefore, call routes need to be updated with significant frequency and, as a result, there is the associated need to update the translations. For example, in Wireless Technologies, as end-users move around (e.g., roam) with a mobile handset, the end-user may access the network through different entry points. As a result, the call routing paths are continually changing.
In systems implementing Local Number Portability (LNP), a similar activity occurs. LNP is a circuit-switched network capability, which allows an end-user to change a service provider and/or service type without changing their phone number. A location Routing Number (LRN) is used to implement the LNP technology. LRN is a 6-digit number used to uniquely identify a switch that has ported numbers (e.g., LNP numbers). LRN assigns the unique 6-digit routing number to each switch in a defined geographic area. As a result, the LRN serves as a network address. Carriers routing telephone calls to end-users that have transferred their telephone numbers from one carrier to another perform a database query to obtain the LRN that corresponds to the dialed telephone number. The carrier then routes the call to the new carrier based on the LRN.
As voice networks have incorporated these various technologies and there is quicker time to market, the use of traditional methods to update network routing, such as receiving an industry feed to the routing OS and then downloading the routing OS to the switches in the network, serves as a continuing impediment to the quick deployment of networks. The routing OS technology limits the ability of a designer to take advantage of the full potential of the new technology.
Thus, there is a need in the art for a method of learning, managing and maintaining valid call routes in a voice network. There is a need in the art for a method and apparatus for learning, managing and maintaining valid call routes across diverse and evolving technologies. There is a need in the art for a method and apparatus for optimizing routing in a network with dynamic and changing numbers and network entry points. There is a need in the art for a method and apparatus which performs routing and updating of translations, taking advantage of new technologies, while reducing time to market.